Method of optimizing tension in applying leg elastics

ABSTRACT

A method of applying leg elastics to absorbent garments involves varying the number and position of feed nips and idler rolls and optimizing the tension between multiple elastic members. The elastic members are bonded to a substrate with variable tension. More particularly, higher tension is provided in the areas of the garment where greater gasketing pressure is required, while lower tension is provided in areas where greater comfort is desired and high gasketing pressure is not needed. Furthermore, each elastic member may vary in degrees of tension from the other elastic members. The resulting garments have optimized comfort, fit and containment about the leg openings.

FIELD OF THE INVENTION

[0001] This invention is directed to a method of optimizing tensiondistribution in the application of leg elastics to a garment. The methodinvolves varying the number and position of feed nips and idler rollsand varying elongation of the elastic members.

BACKGROUND OF THE INVENTION

[0002] Pant-like absorbent garments, such as adult incontinence wear,infant and children's diapers, swim wear and training pants, typicallyinclude a pair of leg openings having an elastic portion around each legopening. The elastic portions are intended to fit snugly around awearer's legs to prevent leakage from the garment. However, more tensionis required in certain areas around the leg, such as in the crotch area,than in other areas around the leg, such as in the area away from thecrotch.

[0003] Various technologies are known for applying leg elastics to sucharticles. For example, some technologies involve increasing spacingbetween elastic members at the crotch area around each leg opening. Thistype of spacing is the normal process fallout due to the correspondencebetween the angle of application and the spacing between the elasticmembers. More particularly, when the elastic members are applied to agarment in a machine direction, variations in the angle of applicationresult in variations in spacing. When a device used to apply the elasticmembers aligns the elastic members in the crotch area in a rowsubstantially perpendicular to the machine direction, as the elasticmembers are guided away from the crotch area, the angle between the rowand the machine direction is closer to 0°, thereby resulting in widerspacing in the crotch area and narrower spacing in the area away fromthe crotch. Other technologies boast consistent spacing between elasticmembers around the entire leg opening. Some of the technologiesmentioned, and others, include consistent tension among elastic membersaround the entire leg opening.

[0004] There is a need or desire for a process for optimizing gasketingpressure around the leg openings of pant-like absorbent garments toprovide enhanced comfort, fit and containment about the leg openings ofsuch garments.

SUMMARY OF THE INVENTION

[0005] It has been found that variations in tension among elasticmembers cause variations in gasketing pressure and can be optimized toprovide enhanced comfort, fit and containment about the leg openings.

[0006] The present invention is directed to a method of applying legelastics to pant-like absorbent garments using variable tension amongthe elastic members. The result is a garment with regions of customizedhigher tension for higher gasketing and regions of lower tension forgreater comfort.

[0007] Apparatus that can be used for carrying out the inventionincludes a pivot arm that can be aligned substantially parallel orperpendicular to a substrate, or anywhere in between, with respect tothe machine direction. The pivot arm can pivot from side to side acrossthe substrate as the substrate travels through a pair of nip rolls inthe machine direction. The pivot arm guides the elastic members as theelastic members are fed through a feed nip. The placement of the feednip for the elastic members results in increased tension as the pivotarm moves the elastic members away from the feed nip. Conversely, as thepivot arm moves the elastic members toward the feed nip, the tension isreduced. The tension can be controlled in this manner such that highertension can be applied in the desired area of the pant and lower tensioncan be applied in areas of the pant where less gasketing pressure isrequired.

[0008] In another embodiment of the invention, separate feed nips areprovided for each elastic member. As a result, the tension profile ofeach elastic member can be different. The placement of the feed niprelative to the corresponding elastic guide at any given pivot armposition determines the tension profile in the elastic member, even ifthe feed nips are driven at the same constant speed.

[0009] In a further embodiment of the invention, idler rolls are locatedin various positions. As a result, the tension profile of each elasticmember can be different. More specifically, a strategically placedelastic feed nip and a corresponding idler roll change the stretchingamount of each individual elastic member such that a different and evenopposite tension gradient can be placed on members that are side by sidein the product composite.

[0010] In yet another embodiment of the invention, an idler roll on ashaft connected to a rotating wheel is used to control elongation of theelastic members. Virtually any type of tension profile can be createdwith this method.

[0011] With the foregoing in mind, it is a feature and advantage of theinvention to provide a method of applying leg elastics to an absorbentgarment resulting in optimized performance of the leg elastics in termsof comfort, fit and containment.

[0012] It is another feature and advantage of the invention to provide amethod of tailoring leg elastic tension in an absorbent garment to fit awearer's body.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side perspective view of an absorbent garment;

[0014]FIG. 2 is a plan view of the absorbent garment of FIG. 1 in apartially disassembled, stretched flat state, and showing the surface ofthe article that faces the wearer when the article is worn, and withportions cut away to show the underlying features;

[0015]FIG. 3 is a top plan view of apparatus used for applying legelastics to an absorbent garment according to one embodiment of theinvention;

[0016]FIG. 4 is a top plan view of apparatus used for applying legelastics to an absorbent garment according to a second embodiment of theinvention;

[0017]FIG. 5 is a top plan view of apparatus used for applying legelastics to an absorbent garment according to a third embodiment of theinvention;

[0018]FIG. 6 is a side view of apparatus used for varying elongation ofelastic members;

[0019]FIG. 7 is a side view of any of FIGS. 3-5; and

[0020]FIG. 8 is an alternative side view of any of FIGS. 3-5.

DEFINITIONS

[0021] Within the context of this specification, each term or phrasebelow will include the following meaning or meanings.

[0022] “Bonded” refers to the joining, adhering, connecting, attaching,or the like, of two elements. Two elements will be considered to bebonded together when they are bonded directly to one another orindirectly to one another, such as when each is directly bonded tointermediate elements.

[0023] “Connected” refers to the joining, adhering, bonding, attaching,or the like, of two elements. Two elements will be considered to beconnected together when they are connected directly to one another orindirectly to one another, such as when each is directly connected tointermediate elements.

[0024] “Disposable” refers to articles which are designed to bediscarded after a limited use rather than being laundered or otherwiserestored for reuse.

[0025] “Disposed,” “disposed on,” and variations thereof are intended tomean that one element can be integral with another element, or that oneelement can be a separate structure bonded to or placed with or placednear another element.

[0026] “Elastic,” “elasticized” and “elasticity” mean that property of amaterial or composite by virtue of which it tends to recover itsoriginal size and shape after removal of a force causing a deformation.

[0027] “Elastomeric” refers to a material or composite which can beelongated by at least 25 percent of its relaxed length and which willrecover, upon release of the applied force, at least 10 percent of itselongation. It is generally preferred that the elastomeric material orcomposite be capable of being elongated by at least 100 percent, morepreferably by at least 300 percent, of its relaxed length and recover,upon release of an applied force, at least 50 percent of its elongation.

[0028] “Film” refers to a thermoplastic film made using a film extrusionand/or foaming process, such as a cast film or blown film extrusionprocess. The term includes apertured films, slit films, and other porousfilms which constitute liquid transfer films, as well as films which donot transfer liquid. The term also includes film-like materials thatexist as open-celled foams.

[0029] “Force” includes a physical influence exerted by one body onanother which produces acceleration of bodies that are free to move anddeformation or separation of bodies that are not free to move.

[0030] “Hydrophilic” describes fibers or the surfaces of fibers whichare wetted by the aqueous liquids in contact with the fibers. The degreeof wetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90° are designated “wettable” orhydrophilic, while fibers having contact angles greater than 90° aredesignated “nonwettable” or hydrophobic.

[0031] “Layer” when used in the singular can have the dual meaning of asingle element or a plurality of elements.

[0032] “Leg elastic” includes elastic bands, strands, ribbons,filaments, filament bunches and the like, which are adjacent to agarment opening that receives a wearer's leg.

[0033] “Liquid impermeable,” when used in describing a layer ormulti-layer laminate, means that a liquid, such as urine, will not passthrough the layer or laminate, under ordinary use conditions, in adirection generally perpendicular to the plane of the layer or laminateat the point of liquid contact. Liquid, or urine, may spread or betransported parallel to the plane of the liquid impermeable layer orlaminate, but this is not considered to be within the meaning of “liquidimpermeable” when used herein.

[0034] “Liquid-permeable material” or “liquid water-permeable material”refers to a material present in one or more layers, such as a film,nonwoven fabric, or open-celled foam, which is porous, and which iswater permeable due to the flow of water and other aqueous liquidsthrough the pores. The pores in the film or foam, or spaces betweenfibers or filaments in a nonwoven web, are large enough and frequentenough to permit leakage and flow of liquid water through the material.

[0035] “Longitudinal” and “transverse” have their customary meaning, asindicated by the longitudinal and transverse axes depicted in FIG. 2.The longitudinal axis lies in the plane of the article and is generallyparallel to a vertical plane that bisects a standing wearer into leftand right body halves when the article is worn. The transverse axis liesin the plane of the article generally perpendicular to the longitudinalaxis. The article as illustrated is longer in the longitudinal directionthan in the transverse direction.

[0036] “Meltblown fibers” means fibers formed by extruding a moltenthermoplastic material through a plurality of fine, usually circular,die capillaries as molten threads or filaments into converging highvelocity heated gas (e.g., air) streams which attenuate the filaments ofmolten thermoplastic material to reduce their diameter, which may be tomicrofiber diameter. Thereafter, the meltblown fibers are carried by thehigh velocity gas stream and are deposited on a collecting surface toform a web of randomly dispersed meltblown fibers. Such a process isdisclosed for example, in U.S. Pat. No. 3,849,241 to Butin et al.Meltblown fibers are microfibers which may be continuous ordiscontinuous, are generally smaller than about 0.6 denier, and aregenerally self bonding when deposited onto a collecting surface.Meltblown fibers used in the present invention are preferablysubstantially continuous in length.

[0037] “Member” when used in the singular can have the dual meaning of asingle element or a plurality of elements.

[0038] “Nonwoven” and “nonwoven web” refer to materials and webs ofmaterial which are formed without the aid of a textile weaving orknitting process.

[0039] “Operatively joined,” in reference to the attachment of anelastic member to another element, means that the elastic member whenattached to or connected to the element, or treated with heat orchemicals, by stretching, or the like, gives the element elasticproperties; and with reference to the attachment of a non-elastic memberto another element, means that the member and element can be attached inany suitable manner that permits or allows them to perform the intendedor described function of the composite. The joining, attaching,connecting or the like can be either directly, such as joining eithermember directly to an element, or can be indirectly by means of anothermember disposed between the first member and the first element, or canbe such that the first member is mechanically trapped by adjacent bondpoints in the first element such that the first member causes thecomposite to exhibit characteristics of the first member.

[0040] “Permanently bonded” refers to the joining, adhering, connecting,attaching, or the like, of two elements of an absorbent garment suchthat the elements tend to be and remain bonded during normal useconditions of the absorbent garment.

[0041] “Polymers” include, but are not limited to, homopolymers,copolymers, such as, for example, block, graft, random and alternatingcopolymers, terpolymers, etc. and blends and modifications thereof.Furthermore, unless otherwise specifically limited, the term “polymer”shall include all possible geometrical configurations of the material.These configurations include, but are not limited to isotactic,syndiotactic and atactic symmetries.

[0042] “Pressure” refers to a force per unit area as applied to thewearer's skin to provide gasketing.

[0043] “Spunbonded fibers” refers to small diameter fibers which areformed by extruding molten thermoplastic material as filaments from aplurality of fine capillaries of a spinnerette having a circular orother configuration, with the diameter of the extruded filaments thenbeing rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 toAppel et al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat.No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394to Kinney, U.S. Pat. No. 3,502,763 to Hartmann, U.S. Pat. No. 3,502,538to Petersen, and U.S. Pat. No. 3,542,615 to Dobo et al., each of whichis incorporated herein in its entirety by reference. Spunbond fibers arequenched and generally not tacky when they are deposited onto acollecting surface. Spunbond fibers are generally continuous and oftenhave average deniers larger than about 0.3, more particularly, betweenabout 0.6 and 10.

[0044] “Stretchable” means that a material can be stretched, withoutbreaking, by at least 50% (to 150% of its initial (unstretched) length)in at least one direction, suitably by at least 100% (to 200% of itsinitial length), desirably by at least 150% (to at least 250% of itsinitial length).

[0045] “Surface” includes any layer, film, woven, nonwoven, laminate,composite, or the like, whether pervious or impervious to air, gas,and/or liquids.

[0046] “Tension” includes a uniaxial force tending to cause theextension of a body or the balancing force within that body resistingthe extension.

[0047] “Thermoplastic” describes a material that softens when exposed toheat and which substantially returns to a nonsoftened condition whencooled to room temperature.

[0048] These terms may be defined with additional language in theremaining portions of the specification.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0049] The principles of the present invention can be incorporated intoany suitable disposable absorbent article. Examples of such suitablearticles include diapers, training pants, feminine hygiene products,incontinence products, other personal care or health care garments, orthe like. As used herein, the term “incontinence products” includesabsorbent underwear for children, absorbent garments for children oryoung adults with special needs such as autistic children or others withbladder/bowel control problems as a result of physical disabilities, aswell as absorbent garments for incontinent older adults. For ease ofexplanation, the description hereafter will be in terms of a child'straining pant.

[0050] Referring to FIG. 1, a disposable absorbent article, such as atraining pant 20, is illustrated in a partially fastened condition. Thetraining pant 20 comprises an absorbent chassis 32 and leg elasticmembers 58. The absorbent chassis 32 defines a front waist region 22, aback waist region 24, a crotch region 26 interconnecting the front andback waist regions, an inner surface 28 which is configured to contactthe wearer, and an outer surface 30 opposite the inner surface which isconfigured to contact the wearer's clothing. With additional referenceto FIG. 2, the absorbent chassis 32 also defines a pair of transverselyopposed side edges 36 and a pair of longitudinally opposed waist edges,which are designated front waist edge 38 and back waist edge 39. Thefront waist region 22 is contiguous with the front waist edge 38, andthe back waist region 24 is contiguous with the back waist edge 39.

[0051] The illustrated absorbent chassis 32 comprises a somewhatrectangular composite structure 33, a pair of transversely opposed frontside panels 34, and a pair of transversely opposed back side panels 134.The composite structure 33 and side panels 34 and 134 may be integrallyformed or comprise two or more separate elements, as shown in FIG. 2.The illustrated composite structure 33 comprises an outer cover 40, abodyside liner 42 which is connected to the outer cover in a superposedrelation, an absorbent assembly 44 which is located between the outercover and the bodyside liner, and a pair of containment flaps 46. Therectangular composite structure 33 has opposite linear end edges 45 thatform portions of the front and back waist edges 38 and 39, and oppositelinear side edges 47 that form portions of the side edges 36 of theabsorbent chassis 32. Leg openings 52 (FIG. 1) are generally defined byportions of the transversely opposed side edges 36 in the crotch region26. For reference, arrows 48 and 49 depicting the orientation of thelongitudinal axis and the transverse axis, respectively, of the trainingpant 20 are illustrated in FIG. 2.

[0052] The leg elastic members 58 are operatively joined to the outercover 40 and/or bodyside liner 42 along the opposite edges 36 andpositioned in the crotch region 26 of the training pant 20 to preventleakage. When tension distribution in the leg elastic members 58 isoptimized, as in the present invention, the performance of the legelastic members 58, in terms of comfort, fit and containment, is alsooptimized. More specifically, higher tension provides improvedcontainment while lower tension provides improved comfort. As usedherein, the term “crotch region” refers to the area of the garment 20located between a wearer's legs. The areas of the garment 20 located infront of a wearer's legs, behind the wearer's legs and on outer portionsof the wearer's legs are considered to be away from, or outside of, thecrotch region 26.

[0053] One example of apparatus for carrying out the invention is showngenerally in FIG. 3. The apparatus 3 includes a pair of pivot arms 18having elastic guide openings 17. Leg elastic members 58 are fed througha strategically placed feed nip 25 (including nip rolls 21 and 23) andthen through the elastic guide openings 17 prior to placement on asubstrate 13 to which the leg elastic members 58 are eventually bondedas the substrate 13 and the leg elastic members 58 pass through a pairof nip rolls 14 and 15. The pivot arms 18 can pivot in a plane eitherparallel (FIG. 7) or perpendicular (FIG. 8) to the substrate 13 as thesubstrate travels through the nip rolls 14 and 15 in a machine direction(indicated by the arrows in FIGS. 3-8). As used herein, the term“machine direction” means the length of a fabric in the direction inwhich it is produced. Alternatively, the pivot arms 18 can pivot in aplane at an angle between parallel and perpendicular to the substrate13.

[0054] Each elastic guide opening 17 on the pivot arm 18 preferablyguides an individual leg elastic member 58. As the pivot arm 18 movesthe elastic guide openings 17 away from the feed nip 25, tension in theleg elastic members 58 increases. As the substrate 13 travels in themachine direction prior to passing through the pair of nip rolls 14 and15, the leg elastic members 58 are bonded, also in the machinedirection, along, near, or between outer edges 37 of the substrate 13.Leg contours 27 can be pre-cut along the outer edges 37 of the substrate13 or may be cut along the contour of the leg elastic members 58subsequent to the bonding process. As the elastic guide openings 17guide the leg elastic members 58 toward the crotch region 26, theelastic guide openings 17 are moved away from the feed nip 25, therebycausing increased tension in the leg elastic members 58 as the legelastic members 58 are bonded to the substrate 13. Conversely, as theelastic guide openings 17 are moved toward the feed nip 25, the pathlength decreases, thereby causing decreased tension in the leg elasticmembers 58. The regions in which the leg elastic members 58 are bondedto the substrate 13 ultimately end up forming the leg openings 52 (FIG.1).

[0055] Another example of apparatus for carrying out the invention isshown generally in FIG. 4. Like the apparatus 3 in FIG. 3, thisapparatus 3 includes a pair of pivot arms 18 having elastic guideopenings 17, but instead of just one strategically placed feed nip 25for each pivot arm 18, this apparatus includes a separate, strategicallyplaced feed nip 25 (including nip rolls 21 and 23) for each leg elasticmember 58. By having separate feed nips 25 for each leg elastic member58, the tension profile of each leg elastic member 58 can be different.As the pivot arm 18 moves the elastic guide openings 17 away from eachof the feed nips 25, tension in the respective leg elastic members 58increases. The ratio of the leg elastic member path length between thefeed nip 25 and the corresponding elastic guide opening 17 at any givenpivot arm position determines the elastic tension profile in the legelastic member 58. When the path is decreasing, the respective member 58undergoes less stretching and thereby exhibits less tension. When thepath is increasing, the member 58 undergoes greater stretching andexhibits greater tension. The respective speeds of the feed nips 25 andthe nip rolls 14, 15 also affects elastic tension of the members 58. Thefeed nips 25 can be driven at the same constant speed for uniformtension profiles among the leg elastic members 58, or at differentspeeds for varying tension profiles. Like the apparatus in FIG. 3, asthe elastic guide openings 17 guide the leg elastic members 58 towardthe crotch region 26, the elastic guide openings 17 are moved away fromthe feed nips 25, thereby causing increased tension in the leg elasticmembers 58 as the leg elastic members 58 are bonded to the substrate 13.

[0056] Yet another example of apparatus for carrying out the inventionis shown generally in FIG. 5. Like the apparatuses in FIGS. 3 and 4,this apparatus 3 includes a pair of pivot arms 18 having elastic guideopenings 17 and at least one strategically placed feed nip 25 for eachpivot arm 18. However, this apparatus 3 also features at least onestrategically placed idler roll 12 to change the path length, and thestretching amount, of individual leg elastic members 58. By locating theidler rolls 12 in various positions, the tension profile of each legelastic member 58 can be different. For example, with an idler roll 12on a pivot point 16 of the pivot arm 18, as shown in a position 51 inFIG. 5, the tension in the corresponding leg elastic member 58 will beconstant. With an idler roll 12 closer to the crotch region 26, as shownin a position 53 in FIG. 5, the path length will increase as the pivotarm 18 moves away from the crotch region 26 and thus the tension will behigher in the corresponding leg elastic member 58. In contrast, when theleg elastic member 58 is not wrapped about an idler roll 12, and thefeed nip 25 is located close to the pivot arm 18 when the pivot arm 18is pivoted away from the crotch region 26, as shown in a position 55 inFIG. 5, the path length will decrease as the pivot arm 18 moves awayfrom the crotch region 26, thereby decreasing the tension in the legelastic member 58.

[0057] Another arrangement for varying tension along the leg elasticmembers 58 is shown in FIG. 6. The arrangement includes an idler roll 12on a shaft 29 connected to a rotating wheel 31. The elongation, andresulting tension, of the leg elastic member 58 is varied based on thedistance from the feed nip 25 to the pair of nip rolls 14, 15 and theamount of deflection created by the rotating wheel 31. Furthermore,offsetting the rotating wheel's 31 axis of rotation or using cams canproduce non-symmetrical tension profiles. As explained, the tension ispreferably higher in the crotch region 26 and lower in areas away fromthe crotch region 26. For example, the elongation range can be only 10%elongation in areas away from the crotch region 26 and in a range ofaround 250-300% elongation in the crotch region 26.

[0058] A wide variety of elastic materials may be used for the legelastic members 58. As is well known to those skilled in the art,suitable elastic materials include sheets, strands or ribbons of naturalrubber, synthetic rubber, or thermoplastic elastomeric polymers. Theelastic materials can be stretched and adhered to a substrate, adheredto a gathered substrate, or adhered to a substrate and then elasticizedor shrunk, for example with the application of heat; such that elasticconstrictive forces are imparted to the substrate. A bonding device 11is shown generally in FIGS. 6-8. In one particular embodiment, forexample, the leg elastic members 58 comprise a plurality of dry-spuncoalesced multifilament spandex elastomeric threads sold under the tradename LYCRA® and available from E. I. DuPont de Nemours and Company,Wilmington, Del., U.S.A.

[0059] The leg elastic members 58 preferably have elongation of 25-350%,more preferably about 30-260%, most preferably about 35-200%.

[0060] The substrate 13 is preferably the outer cover 40 and desirablycomprises a material that is substantially liquid impermeable, and canbe elastic, stretchable or nonstretchable. The outer cover 40 can be asingle layer of liquid impermeable material, but desirably comprises amulti-layered laminate structure in which at least one of the layers isliquid impermeable. For instance, the outer cover 40 can include aliquid permeable outer layer and a liquid impermeable inner layer thatare suitably joined together by a laminate adhesive (not shown).Suitable laminate adhesives, which can be applied continuously orintermittently as beads, a spray, parallel swirls, or the like, can beobtained from Findley Adhesives, Inc., of Wauwatosa, Wis., U.S.A., orfrom National Starch and Chemical Company, Bridgewater, N.J., U.S.A. Theliquid permeable outer layer can be any suitable material and desirablyone that provides a generally cloth-like texture. One example of such amaterial is a 20 gsm (grams per square meter) spunbond polypropylenenonwoven web. The outer layer may also be made of those materials ofwhich liquid permeable bodyside liner 42 is made. While it is not anecessity for the outer layer to be liquid permeable, it is desired thatit provides a relatively cloth-like texture to the wearer.

[0061] The inner layer of the outer cover 40 can be both liquid andvapor impermeable, or can be liquid impermeable and vapor permeable. Theinner layer is desirably manufactured from a thin plastic film, althoughother flexible liquid impermeable materials may also be used. The innerlayer, or the liquid impermeable outer cover 40 when a single layer,prevents waste material from wetting articles, such as bedsheets andclothing, as well as the wearer and caregiver. A suitable liquidimpermeable film for use as a liquid impermeable inner layer, or asingle layer liquid impermeable outer cover 40, is a 0.02 millimeterpolyethylene film commercially available from Huntsman Packaging ofNewport News, Va., U.S.A. If the outer cover 40 is a single layer ofmaterial, it can be embossed and/or matte finished to provide a morecloth-like appearance. As earlier mentioned, the liquid impermeablematerial can permit vapors to escape from the interior of the disposableabsorbent article, while still preventing liquids from passing throughthe outer cover 40. A suitable “breathable” material is composed of amicroporous polymer film or a nonwoven fabric that has been coated orotherwise treated to impart a desired level of liquid impermeability. Asuitable microporous film is a PMP-1 film material commerciallyavailable from Mitsui Toatsu Chemicals, Inc., Tokyo, Japan, or anXKO-8044 polyolefin film commercially available from 3M Company,Minneapolis, Minn.

[0062] As mentioned, the leg elastic members 58 can be bonded to theouter cover 40 and/or the bodyside liner 42. FIGS. 6-8 show the legelastic members 58 being bonded to the outer cover 40 and the bodysideliner 42 at the same time. In this embodiment, the leg elastic members58 are essentially sandwiched between the outer cover 40 and thebodyside liner 42.

[0063] The liquid permeable bodyside liner 42 is illustrated asoverlying the outer cover 40 and absorbent assembly 44 (FIG. 2), and maybut need not have the same dimensions as the outer cover 40. Thebodyside liner 42 is desirably compliant, soft feeling, andnon-irritating to the child's skin. Further, the bodyside liner 42 canbe less hydrophilic than the absorbent assembly 44, to present arelatively dry surface to the wearer and permit liquid to readilypenetrate through its thickness.

[0064] The bodyside liner 42 can be manufactured from a wide selectionof web materials, such as synthetic fibers (for example, polyester orpolypropylene fibers), natural fibers (for example, wood or cottonfibers), a combination of natural and synthetic fibers, porous foams,reticulated foams, apertured plastic films, or the like. Various wovenand nonwoven fabrics can be used for the bodyside liner 42. For example,the bodyside liner can be composed of a meltblown or spunbonded web ofpolyolefin fibers. The bodyside liner can also be a bonded-carded webcomposed of natural and/or synthetic fibers. The bodyside liner can becomposed of a substantially hydrophobic material, and the hydrophobicmaterial can, optionally, be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.For example, the material can be surface treated with about 0.28 weightpercent of a surfactant commercially available from the Rohm and HaasCo. under the trade designation Triton X-102. The surfactant can beapplied by any conventional means, such as spraying, printing, brushcoating or the like. The surfactant can be applied to the entirebodyside liner 42 or can be selectively applied to particular sectionsof the bodyside liner, such as the medial section along the longitudinalcenterline.

[0065] A suitable liquid permeable bodyside liner 42 is a nonwovenbicomponent web having a basis weight of about 27 gsm. The nonwovenbicomponent can be a spunbond bicomponent web, or a bonded cardedbicomponent web. Suitable bicomponent staple fibers include apolyethylene/polypropylene bicomponent fiber available from CHISSOCorporation, Osaka, Japan. In this particular bicomponent fiber, thepolypropylene forms the core and the polyethylene forms the sheath ofthe fiber. Other fiber orientations are possible, such as multi-lobe,side-by-side, end-to-end, or the like. While the outer cover 40 andbodyside liner 42 can comprise elastomeric materials, it can bedesirable in some embodiments for the composite structure to begenerally inelastic, where the outer cover, the bodyside liner and theabsorbent assembly comprise materials that are generally notelastomeric.

[0066] The absorbent assembly 44 (FIG. 2) is positioned between theouter cover 40 and the bodyside liner 42, which components can be joinedtogether by any suitable means, such as adhesives, as is well known inthe art. The absorbent assembly 44 can be any structure which isgenerally compressible, conformable, non-irritating to the child's skin,and capable of absorbing and retaining liquids and certain body wastes.The absorbent assembly 44 can be manufactured in a wide variety of sizesand shapes, and from a wide variety of liquid absorbent materialscommonly used in the art. For example, the absorbent assembly 44 cansuitably comprise a matrix of hydrophilic fibers, such as a web ofcellulosic fluff, mixed with particles of a high-absorbency materialcommonly known as superabsorbent material. In a particular embodiment,the absorbent assembly 44 comprises a matrix of cellulosic fluff, suchas wood pulp fluff, and superabsorbent hydrogel-forming particles. Thewood pulp fluff can be exchanged with synthetic, polymeric, meltblownfibers or with a combination of meltblown fibers and natural fibers. Thesuperabsorbent particles can be substantially homogeneously mixed withthe hydrophilic fibers or can be nonuniformly mixed. The fluff andsuperabsorbent particles can also be selectively placed into desiredzones of the absorbent assembly 44 to better contain and absorb bodyexudates. The concentration of the superabsorbent particles can alsovary through the thickness of the absorbent assembly 44. Alternatively,the absorbent assembly 44 can comprise a laminate of fibrous webs andsuperabsorbent material or other suitable means of maintaining asuperabsorbent material in a localized area.

[0067] Suitable superabsorbent materials can be selected from natural,synthetic, and modified natural polymers and materials. Thesuperabsorbent materials can be inorganic materials, such as silicagels, or organic compounds, such as crosslinked polymers. Suitablesuperabsorbent materials are available from various commercial vendors,such as Dow Chemical Company located in Midland, Mich., U.S.A., andStockhausen GmbH & Co. KG, D-47805 Krefeld, Federal Republic of Germany.Typically, a superabsorbent material is capable of absorbing at leastabout 15 times its weight in water, and desirably is capable ofabsorbing more than about 25 times its weight in water.

[0068] In one embodiment, the absorbent assembly 44 is generallyrectangular in shape, and comprises a blend of wood pulp fluff andsuperabsorbent material. One preferred type of fluff is identified withthe trade designation CR1654, available from U.S. Alliance,Childersburg, Ala., U.S.A., and is a bleached, highly absorbent sulfatewood pulp containing primarily soft wood fibers. As a general rule, thesuperabsorbent material is present in the absorbent assembly 44 in anamount of from about 0 to about 90 weight percent based on total weightof the absorbent assembly. The absorbent assembly 44 suitably has adensity within the range of about 0.10 to about 0.35 grams per cubiccentimeter. The absorbent assembly 44 may or may not be wrapped orencompassed by a suitable tissue wrap that maintains the integrityand/or shape of the absorbent assembly.

[0069] The absorbent chassis 32 can also incorporate other materialsthat are designed primarily to receive, temporarily store, and/ortransport liquid along the mutually facing surface with the absorbentassembly 44, thereby maximizing the absorbent capacity of the absorbentassembly. One suitable material is referred to as a surge layer (notshown) and comprises a material having a basis weight of about 50 gramsper square meter, and including a through-air-bonded-carded web of ahomogenous blend of 60 percent 3 denier bicomponent fiber including apolyester core/polyethylene sheath, commercially available from BASFCorporation, and 40 percent 6 denier polyester fiber, commerciallyavailable from Hoechst Celanese Corporation, in Portsmouth, Va., U.S.A.

[0070] As noted previously, the illustrated training pant 20 has frontand back side panels 34 and 134 disposed on each side of the absorbentchassis 32 (FIGS. 1 and 2). These transversely opposed front side panels34 and transversely opposed back side panels 134 can be permanentlybonded to the composite structure 33 of the absorbent chassis 32 in therespective front and back waist regions 22 and 24, and are releasablyattached to one another by a fastening system 80. More particularly, asshown best in FIG. 2, the front side panels 34 can be permanently bondedto and extend transversely beyond the linear side edges 47 of thecomposite structure 33 in the front waist region 22 along attachmentlines 66, and the back side panels 134 can be permanently bonded to andextend transversely beyond the linear side edges of the compositestructure in the back waist region 24 along attachment lines 66. Theside panels 34 and 134 may be attached using attachment means known tothose skilled in the art such as adhesive, thermal or ultrasonicbonding. The side panels 34 and 134 can also be formed as a portion of acomponent of the composite structure 33, such as the outer cover or thebodyside liner.

[0071] Each of the side panels 34 and 134 can include one or moreindividual, distinct pieces of material. In particular embodiments, forexample, each side panel 34 and 134 can include first and second sidepanel portions that are joined at a seam, with at least one of theportions including an elastomeric material (See FIG. 2). Stillalternatively, each individual side panel 34 and 134 can include asingle piece of material which is folded over upon itself along anintermediate fold line (not shown).

[0072] The side panels 34 and 134 desirably comprise an elastic materialcapable of stretching in a direction generally parallel to thetransverse axis 49 of the training pant 20. In particular embodiments,the front and back side panels 34 and 134 may each comprise an interiorportion 78 disposed between the distal edge 68 and a respective front orback center panel 35 or 135. In the illustrated embodiment in FIG. 2,the interior portions 78 are disposed between the distal edges 68 andthe side edges 47 of the rectangular composite structure 33. The elasticmaterial of the side panels 34 and 134 can be disposed in the interiorportions 78 to render the side panels elastomeric in a directiongenerally parallel to the transverse axis 49. Most desirably, each sidepanel 34 and 134 is elastomeric from a waist end edge 72 to a leg endedge 70. More specifically, individual samples of side panel material,taken between the waist end edge 72 and the leg end edge 70 parallel tothe transverse axis 49 and having a length from the attachment line 66to the distal edge 68 and a width of about 2 centimeters, are allelastomeric.

[0073] Suitable elastic materials, as well as one described process ofincorporating elastic side panels into a training pant, are described inthe following U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompelet al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohjola; U.S.Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat. No.5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which areincorporated herein by reference. In particular embodiments, the elasticmaterial comprises a stretch-thermal laminate (STL), a neck-bondedlaminated (NBL), a reversibly necked laminate, or a stretch-bondedlaminate (SBL) material. Methods of making such materials are well knownto those skilled in the art and described in U.S. Pat. No. 4,663,220issued May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issuedJul. 13, 1993 to Morman; and European Patent Application No. EP 0 217032 published on Apr. 8, 1987 in the names of Taylor et al.; all ofwhich are incorporated herein by reference. Alternatively, the sidepanel material may comprise other woven or nonwoven materials, such asthose described above as being suitable for the outer cover 40 orbodyside liner 42, or stretchable but inelastic materials.

[0074] The absorbent chassis 32 and the fastening system 80 togetherdefine a refastenable pant having a waist opening 50 and a pair of legopenings 52. When the fastening system is engaged, it can be appreciatedthat the refastenable pant includes a pair of elastomeric front sidepanels 34 extending from the waist opening to each leg opening, a pairof elastomeric back side panels 134 extending from the waist opening toeach leg opening, a pair of refastenable seams 88 (FIG. 1) extendingfrom the waist opening to each leg opening and positioned between theelastomeric front and back side panels, an elastomeric front waistband54 disposed in the front waist region and positioned between the pair ofelastomeric front side panels, an elastomeric back waistband 56 disposedin the back waist region and positioned between the pair of elastomericback side panels, and at least a pair of elastomeric leg members 58which partially encircle each leg opening. More preferably, more thanone elastomeric leg member 58 partially or fully encircles each legopening 52. Each elastomeric leg member 58 extends from adjacent anelastomeric front side panel 34 in the front waist region 22 to adjacentan elastomeric back side panel 134 in the back waist region 24.

[0075] As described herein, the various components of the training pant20 can be integrally assembled together employing various types ofsuitable attachment means, such as adhesive, sonic and thermal bonds orcombinations thereof. The resulting product is an absorbent garmenthaving optimized comfort, fit and containment about the leg openings 52.

[0076] It will be appreciated that details of the foregoing embodiments,given for purposes of illustration, are not to be construed as limitingthe scope of this invention. Although only a few exemplary embodimentsof this invention have been described in detail above, those skilled inthe art will readily appreciate that many modifications are possible inthe exemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention, which is defined in the following claims and all equivalentsthereto. Further, it is recognized that many embodiments may beconceived that do not achieve all of the advantages of some embodiments,particularly of the preferred embodiments, yet the absence of aparticular advantage shall not be construed to necessarily mean thatsuch an embodiment is outside the scope of the present invention.

We claim:
 1. A method of attaching leg elastics to an absorbent garment,comprising the steps of: using a pivot arm to guide at least two elasticmembers from a feed nip onto a substrate; inducing a tension profile inthe elastic members such that at least one of the elastic members isunder a different level of tension than at least another of the elasticmembers through placement of the feed nip relative to the pivot arm;oscillating the pivot arm such that the elastic members increase intension as guide points on the pivot arm move away from the feed nip,and decrease in tension as the guide points move towards the feed nip;and bonding the elastic members to the substrate.
 2. The method of claim1 wherein the elastic members are bonded to the substrate such that thetension profile is incorporated into the substrate.
 3. The method ofclaim 1 wherein an adhesive is used to bond the elastic members to thesubstrate.
 4. The method of claim 1 wherein the elastic members areultrasonically bonded to the substrate.
 5. The method of claim 1 whereinthe pivot arm guides at least three elastic members from the feed niponto the substrate.
 6. The method of claim 1, further comprising thestep of capturing the elastic members between the substrate and a secondlayer while bonding the substrate to the second layer.
 7. A method ofattaching elastic members to an absorbent garment, comprising the stepsof: feeding at least two elastic members through individual feed nips,each feed nip including two nip rolls, wherein the number of feed nipscorresponds to the number of elastic members; using a single pivot armto guide each of the elastic members from the feed nips onto asubstrate; and bonding the elastic members to the substrate.
 8. Themethod of claim 7 further comprising the step of individually increasingtension in each of the elastic members by moving the pivot arm away fromthe feed nips.
 9. The method of claim 7 wherein an adhesive is used tobond the elastic members to the substrate.
 10. The method of claim 7wherein the elastic members are ultrasonically bonded to the substrate.11. The method of claim 7 wherein the pivot arm guides at least threeelastic members from at least three feed nips, through at least threeelastic guides and onto the substrate.
 12. The method of claim 7 whereineach of the feed nips is driven at the same, constant speed.
 13. Themethod of claim 7 wherein at least some of the feed nips are driven atdifferent speeds.
 14. The method of claim 7 further comprising the stepof simultaneously bonding the elastic members to a second layer ofmaterial while bonding the elastic members to the substrate.
 15. Themethod of claim 7, further comprising the step of capturing the elasticmembers between the substrate and a second layer while bonding thesubstrate to the second layer.